Examine source code of Cashback PackBarre

{
  "name": "Cashback PackBarre",
  "manifest_version": 2,
  "description": "Détecte les sites partenaires de PackBarre et vous propose d'activer le cashback facilement.",
  "homepage_url": "https://www.packbarre.com/",
  "version": "1.2resigned1",
  "author": "BPMconcept SAS",
  "icons": {
    "48": "images/icon-48.png",
    "96": "images/icon-96.png"
  },
  "permissions": [
    "webNavigation",
    "<all_urls>",
    "cookies",
    "activeTab"
  ],
  "web_accessible_resources": [
    "images/*",
    "fonts/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{c789081a-a662-4b9e-ba48-aca9fd4633f0}"
    }
  }
}